CBSE Class 10 Science Marking Scheme 2021 is available here for free PDF download. The Central Board of Secondary Education (CBSE) has released the Marking Scheme for Class 10 Science Sample Paper 2021. This marking scheme is helpful to know the suggested answers for all questions given in the sample paper. With the help of this Science marking scheme, students can learn the right method of answering any question. Moreover, the CBSE marking scheme also mentions the criteria according to which marks will be allotted to different answers during the checking of answer sheets of CBSE Class 10 candidates.
Given below are some questions from the CBSE Class 10 Science sample paper and their answers from the CBSE Class 10 Science Marking Scheme:
1. List any two observations when Ferrous Sulphate is heated in a dry test tube?
- Initial light green colour changes to reddish brown colour
- Colourless gas is evolved
- Gas with choking smell is evolved (Any two)
1. Identify the products formed when 1 mL of dil. Hydrochloric acid is added to 1g of Sodium metal?
Sodium Chloride and Hydrogen gas.
2. Write the chemical name and chemical formula of the salt used to remove permanent hardness of water.
Sodium Carbonate decahydrate, Na2CO3.10H2O.
3. Which of the following is not observed in a homologous series? Give reason for your choice.
a) Change in chemical properties
b) Difference in -CH2 and 14u molecular mass
c) Gradation in physical properties
d) Same functional group
(a) Change in chemical properties
It does not occur due to the presence of the same functional group.
4. Why does the Sun appear white at noon?
The light is least scattered at noon.
5. Both a spherical mirror and a thin spherical lens have a focal length of (-)15 cm. What type of mirror and lens are these?
Both are concave. Alternative answer that should be given credit: Plano-concave lens
Also Check: CBSE Class 10 Science Question Paper 2020
6. The image formed by a concave mirror is observed to be real, inverted and larger than the object. Where is the object placed?
Between the principal focus and the centre of curvature.
6. Name the part of a lens through which a ray of light passes without suffering any deviation.
7. In the arrangement shown in figure there are two coils wound on a non-conducting cylindrical rod. Initially the key is not inserted in the circuit. Later the key is inserted and then removed shortly after.
What are the two observations that can be noted from the galvanometer reading?
There are momentary galvanometer deflections that die out shortly; the deflections are in opposite directions.
8. Draw the magnetic field lines around a straight current carrying conductor.
The field consists of concentric circles centred on the wire.
Download the complete marking scheme along with the CBSE Maths sample paper from following links: